William Optics GT81 81mm f/5.9 Apo Refractor - Red # A-F81GTIIRD

Product Details

Innovative Bahtinov Mask Cover (Patented) & New Dovetail Plate included!

The new 2018 GT81 three-element super APO offers superb quality for imaging and visual use at an affordable price! From the pristine white finish on the CNC to the elegant red trim, this telescope has more than just good looks...

Optically Unbeatable

• Triplet air-spaced objective (FPL-53) in adjustable CNC machined ultra high precision lens cell.
• Extremely sharp with excellent color correction.
• Each lens is Fully Multi-Coated with a special super-high transmission coating (STM Coating) on all surfaces.
• This f/5.9 lens is ideal for astrophotography.

2.5" R&P Focuser

• 2.5" R&P Ultra robust focuser with 1:10 dual speed: a treat to use during astrophotography
• No image shifting! Heavy duty: perfect for your accessories.

Simply Beautiful Finish and Features

• Pure William Optics quality fit and finish: powder-painted white CNC-machined aluminum tube, red trim finish, retractable dewshield, dewshield cap.
• Includes 50mm finder bracket.
• Top quality anodizing.
• Very compact for carrying on flights.

Attention to Details

• 2" & 1.25" adapter included in the price.
• Anti-marring brass compression rings.
• Though you will never need it, you have a 2-year warranty from WO, and the certainty that we will be there to assist you even beyond that, if you need!

Standard Package

• Mounting Rings
• Guiding Rings
• New Dual-Sided Vixen/Arca-Style Dovetail Rail
• 2.5" R&P Focuser
• Innovative Bahtinov Mask Cover (Patented)
• Soft Carry Case
• Two-year, no fuss warranty and constant customer service

Additional Specifications

• Retracted Length：390mm
• Tube with Rings and Dovetail Weight: 3.84kg

Optional Accessories：

• M63 -2" Rotolock
• 1.25" Rotolock
• All New 50mm/F4 Rotolock Guide scope
• New Full frame x0.8 Flattener

Specification for William Optics Apo Lenses

All William Optics refractor objectives are double tested and inspected by WO at their factory. These telescopes are free of coma and astigmatism. Since all individual lens surfaces are machine coated, sometimes you may notice minor visual imperfections which will not compromise the optical performance of the telescope. The dimensions of scratches and points shall not exceed the following values:

• Scratches - Maximum Width: 0.025 mm
• Scratches - Maximum Length: 1/4 of total lens diameter
• Scratches - Maximum Quantity: Three
• Dots or Spot Points - Maximum Diameter: 0.4 mm
• Dots or Spot Points - Maximum Quantity: Three
• Accumulation of Defects - Limited Area: 0.8mm^2
• Accumulation of Defects - Total Area: 5.8mm^2